The Syrian army and allied fighters captured large swathes of the southeastern countryside of the northern province of Raqqa, following intense battles with the Islamic State (IS) militants, a monitor group reported.

The Syrian troops reached the area between the eastern countryside of Raqqa, the de facto capital of IS and the countryside of the eastern province of Deir al-Zour, becoming nine kilometers from the administrative borders of Deir al-Zour, said the Syrian Observatory for Human Rights.

Reaching the outskirts of Deir al-Zour is a priority for the Syrian army in its bid to clear that key oil-rich province from the IS militants and break the siege imposed by the terror-designated group in the city.

The progress in the eastern and southern countryside of Raqqa comes after the Syrian forces ended the IS control in the western countryside of that province since the Syrian forces and allied fighters unleashed their operations in Raqqa countryside last month.

The Observatory, which relies on a network of activists on the ground, said the progress of the Syrian army comes as the U.S.-led Syrian Democratic Forces (SDF) have made more gains in Raqqa city.

It added that the operations by both the U.S.-backed SDF and the Russian-supported Syrian forces are coordinated between Russia and the U.S., as part of the sharing influence agreement in northern Syrian between both powers.

Experts believe that the undeclared agreement includes allowing the SDF to take control over Raqqa city, while the Syrian forces will wrest control over the IS-held areas in Raqqa countryside and in Deir al-Zour province.

With both the SDF and the Syrian army advancing in Raqqa, the IS is only in control of 10 percent of Raqqa province, with the SDF controlling 67.90 percent of Raqqa province while the Syrian government forces controlling 22.54 percent of the province.

The IS is left with 9.56 percent control in that province, according to the Observatory.

source: xinhua